Solar Orbiter – Mission Update
Industrial Assessment Studies – key
results
• Reference launch: Oct 2013 (back-up: May 2015).
• Baseline mission design retained by both
contractors after Mid Term Meeting (direct
injection, SEP, 1.5 yr cruise, 3.2 yr nominal science phase, 2.4 yr
extended science phase).
• Back-up mission designs are available but all impact either on
cruise phase duration (up to 5 yr) or on total cost and risk.
• Strong commonality and programmatic link with Bepi Colombo
mission is confirmed (e.g. HGA usable down to 0.3 AU from Sun).
• No technical show-stoppers identified to date. ‘Behind shield’
design is confirmed as most appropriate. Solutions available.
• Tight management of onboard resources is required (mass,
thermal loads, TM link).
• Overall mission complexity lower than Bepi Colombo.
Solar Orbiter – Mission Update
Remote Sensing Instruments:
Ground rules from Integrated Payload Study
-
-
‘1m class’ instruments principle (as instrument size impacts on P/L and
spacecraft dimensions  larger mass)
‘0.5 arcsec/pixel imaging/1 arcsec/pixel spectroscopy’ principle (as
enhanced resolution implies larger apertures  unacceptable heat
loads and again larger mass)
Commensurate focal plane detector size (Max 2k x 2k, as large array
size implies large data volume  excessive TM needs)
Co-alignment of all RS units and design harmonisation (e.g. single
technology for focal plane detectors)
Resources demands compatible with final PDD values and based on a
realistic and thorough estimate.
Keep it simple approach…
Solar Orbiter – Mission Update
Payload Definition Document (PDD)
Consolidation Meeting – ESTEC Nov 1, 2004
Achieved milestones:
- Industrial science payload study - Jan-June 2004
- Internal ESA CDF study - Mar 2004
- Parallel competitive industrial studies (Astrium, Alcatel) – KO
end of April, Mid Term Review - Sep 2004
- PDD revision and release of v3 - Sep 2004
- Draft Technology Development Plan - Oct 2004
Ongoing:
- Consolidation of Payload Definition Document
- Consolidation of the Technology Development Plan
Solar Orbiter – Mission Update
Payload Definition Document (PDD)
Consolidation Meeting – ESTEC Nov 1, 2004
General Notes:
- PDD Version 4 is the last one before the AO,
i.e. it is the one we must get right. Version 3 is
not ‘final’.
- Final presentation from Industrial Study – Dec 14-15 at
ESTEC. PWG chairs to attend.
- AO nominally at end of 2005. Early 2006 more likely
(especially in light of national funding and NASA situation.
Solar Orbiter – Mission Update
Payload Definition Document (PDD)
Consolidation Meeting – ESTEC Nov 1, 2004
Technology Development:
- PWG requested development/test activities, in
particular support for detector development and
optical surface/coating environmental (particle
and thermal) tests. ESTEC now responding.
-
Activities identified by ESTEC for remote sensing payload:
VIM – Fabry-Perot filter
VIM – Polarisation modulation package
VIM – Large narrow bandpass entrance filter
EUS – Radiator grid entrance filter
VIM/EUI/EUS/COR/STIX – Detectors
ALL – Data compression
ALL – Solar environment test facility.
Solar Orbiter – Mission Update
Payload Definition Document (PDD)
Consolidation Meeting – ESTEC Nov 1, 2004
Common Detector Needs:
Given need from ESA for 1 m instruments, and 1 arcsec
spectroscopy (pixel size) & 0.5 arcsec imaging, i.e. 150 km
at perihelion for EUS and 75 km for VIM, EUI, is there a
common need for detectors of 2 k x 2 k at 10 or 8 micron
rather than different values (e.g. the 4 k x 4 k 5 micron
detector for EUS is not driven by spatial
resolution/instrument length).
Does this cater for EUI, EUS, VIM, COR? Consider
wavelength requirements, coatings (if any), compatible with
MCP if COR needs it? Would it still be possible for EUS to
have 5 micron array (for smaller instrument) – risks, optical
performance (1 m instrument).
Solar Orbiter – Mission Update
Payload Definition Document (PDD)
Consolidation Meeting – ESTEC Nov 1, 2004
Data Compression:
Seen as critical BUT action is delayed until instruments
better defined – beyond initial studies already done through
PDD activity.
Solar Orbiter – Mission Update
Payload Definition Document (PDD)
Consolidation Meeting – ESTEC Nov 1, 2004
Solar Environment Test Facility:
Test facility of up to 23 solar constants envisaged by ESTEC
team. Definition meeting this Friday at ESTEC. Sized for
single instruments. Would not include particle environment,
so additional tests would be required.
Can this cover the requirements of the PWG? Who organises
the test programme?
Solar Orbiter – Mission Update
Payload Definition Document (PDD)
Consolidation Meeting – ESTEC Nov 1, 2004
EUS Radiator Grid Entrance:
EUS studies suggest that the radiator grid entrance filter
may add complexity and risk and that it is more elegant to
focus on the primary mirror plus the reflector/heat stop as a
‘simple’ approach.
Action: Having the filter is not a requirement. We need to
show that the latter is OK for ESA to remove the filter option
from their Technology Development Activity list. If the
primary mirror is the main thermal ‘item’, are we
comfortable with SiC – i.e. not worry about the potential
degradation of coatings (gold, multilayers). Comment on
impact of this on wavelength selection.
Solar Orbiter – Mission Update
Payload Definition Document (PDD)
Consolidation Meeting – ESTEC Nov 1, 2004
Pointing & Stability:
Requirements (note x is in the solar direction):
Parameter
Line of sight (x)
Around line of sight
Absolute pointing error
< 2 arcmin
< 20 arcmin
Pointing drift error
< 1 arcmin/10 days
< 10 arcmin/10 days
Relative pointing error
< 1 arcsec/10 sec
< 2 arcsec/10 sec
RPE ‘achieved’
0.5 arcsec/10 sec
Note: 2 arcmin at 0.2 AU is equivalent to 24 arcsec at 1 AU.
Do we need stabilisation systems for a 1 arcsec/pixel spectrometer or a 0.5
arcsec/pixel imager? (EUI PDD was listed as 0.1 arcsec/10 sec when pixel was
0.25 arcsec).
Solar Orbiter – Mission Update
Payload Definition Document (PDD)
Consolidation Meeting – ESTEC Nov 1, 2004
EUI Issues:
Mass
(kg)
Data
rate
(kb/s)
Pixel size
(arcsec)
Pixel size
(km @
0.2AU)
Array
Instrument Size
(cm3)
PDD#1
48.6
20
0.25
37
2k x 2k
180x44x25
PDD#3
15.5
20
0.5
75
2k x 2k
95x50x30
Assume 9-10 micron pixels.
Aperture: Astrium ‘scale down’ had resulted in 1 cm! Key is instrument size,
mass, thermal situation. PDD back at 2 cm but is not a requirement.
Solar Orbiter – Mission Update
Payload Definition Document (PDD)
Consolidation Meeting – ESTEC Nov 1, 2004
EUS Issues:
Mass
(kg)
Data
rate
(kb/s)
Pixel size
(arcsec)
Pixel size
(km @
0.2AU)
Array
Instrument Size
(cm3)
PDD#1
25
17
0.5
75
4k x 4k
160x30x40
PDD#3
16
17
1
150
2k x 2k
80x15x15
PDD#3’
20
17
1
150
2k x 2k
96x24x18
PDD#1 and 3 assume 5 micron pixels. PDD#3’ assumes 8-10 micron pixels.
Solar Orbiter – EUV Spectrometer (EUS)
4th Consortium Meeting – November 4, 2004
http://www.orbiter.rl.ac.uk
Agenda:
09:30-12:30
Solar Orbiter and EUS Status
Richard Harrison/Peter Cargill
Report on Imager Plans
Louise Harra
Scientific Issues
Peter Young
Mechanical & Thermal Overview
Eric Sawyer, with Doug Griffin,
Bryan Shaughnessy.
Optical Design
Kevin Middleton, Roger Thomas,
Luca Poletto, & Clarence Korendyke
(EIS/gratings)
Solar Orbiter – EUV Spectrometer (EUS)
4th Consortium Meeting – November 4, 2004
http://www.orbiter.rl.ac.uk
Agenda:
13:30-17:30
Detector Status
Nick Waltham (APS),
Udo Schuehle (BOLD)
Wavelength Selection (Discussion)
Chair: Peter Young
Consortium Responsibilities (Discussion)
Chair: Richard Harrison
Schedule to AO (Discussion)
Chair: Richard Harrison
Solar Orbiter – EUV Spectrometer (EUS)
4th Consortium Meeting – November 4, 2004
Schedule to AO:
AO
End 2005/Early 2006
Proposal draft production
From November 2005
Pre-Proposal Consortium Meeting
~ September 2005
Detailed design phase
From January 2005
‘Post Feasibility Study’ Consortium Meeting
‘Feasibility phase’
Spring 2005
Two basic design concepts established
Optical, Thermal, feasibility/tradeoffs
Consolidate (in parallel) wavelengths
Define institute responsibilities
Hardware Telecons/Meetings???
ESA Industrial Study Input/PDD4
December
Weekly Local Meetings at RAL
Started…